Question

我是Android编程新手。我正在使用Handler来更改图像，但它应该只发生30秒，之后我想调用另一个活动

我的代码：

imageView = (ImageView) findViewById(R.id.imageView);

final int[] imageArray = {R.drawable.a, R.drawable.b, R.drawable.c, R.drawable.d};

    final Handler handler = new Handler();
    Runnable runnable = new Runnable() {
        int i = 0;
        @Override
        public void run() {
            imageView.setImageResource(imageArray[i]);
            i++;
            if(i>imageArray.length-1){
                i= 0;
            }
            handler.postDelayed(this,100);
        }
    };
   handler.postDelayed(runnable, 3000);

如何在30秒后停止此活动并拨打其他活动？请帮忙

Answer 1

您可以使用计时器尝试此操作..下面的代码将每1秒运行一次代码，直到达到30秒

this.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                int globalTimer = 0;

                // 30 times  30 * 1000 = 30000 == 30 seconds
                int limitTimer = 30;
                int i = 0;

                // create Timer
                Timer timer = new Timer();
                timer.schedule(new TimerTask() {
                    @Override
                    public void run() {
                        globalTimer++;
                        //run your code
                        imageView.setImageResource(imageArray[i]);
                        i++;

                        if(i>imageArray.length-1){
                            i= 0;
                        }

                        //check if globalTimer is equal to limitTimer
                        if (globalTimer == limitTimer) {
                            timer.cancel(); // cancel the Timer
                            // jump to another activity
                            Intent intent = new Intent(Class.this,Name.class);
                            startActivity(intent);
                        }
                    }

                }, 0, 1000);
            }
        });

Answer 2

1）延迟以毫秒为单位，如果您想每秒更改图像handler.postDelayed(this,100);应更改为handler.postDelayed(this,1000);（1s = 1000ms）

2）停止任务：

    long startTime = System.currentTimeMillis();
    final Handler handler = new Handler();
    Runnable runnable = new Runnable() {
        int i = 0;
        @Override
        public void run() {
            imageView.setImageResource(imageArray[i]);
            i++;
            if(i>imageArray.length-1){
                i= 0;
            }
            if (System.currentTimeMillis() - startTime < 30000){
                handler.postDelayed(this,1000);
            } else {
                //TODO start second activity
            }
        }
    };

或者您可以安排第二次运行以在30秒后停止更改图像并开始另一项活动：

    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            handler.removeCallbacks(runnable); //stop next runnable execution

            //TODO start second activity
        }
    }, 30000);

如何在一段时间后停止处理程序（在我的情况下是30秒）？

2 个答案: